1. Field of the Invention
The present invention relates to a detergent composition containing a polyglycerol monoalkyl ether, water, a fat or oil, and a polyol. The detergent composition is useful typically as a cleansing agent for oily cosmetics.
2. Description of the Related Art
Cleansing agents for cosmetics (makeups) are roughly classified mainly oil, gel, and foamable cleansing agents. Oil and gel cleansing agents generally require massaging by fingers so as to satisfactorily mix with cosmetics and to remove the cosmetics. A pressure is applied to the skin upon massaging, and this often damages the skin. In addition, these agents cause sticky feeling upon use and are not readily rinsable. In contrast, foamable cleansing agents are less irritating to the skin, excel in feel upon use, and have thereby been desirably used as cleansing agents.
Known foamable cleansing agents include those containing a foamable aerosol composition that is composed of an oil-in-water (O/W) emulsion including two phases, i.e., an inner phase and an aqueous phase. The inner phase is composed of an oily phase containing a propellant dissolved therein, and the aqueous phase has poor compatibility or miscibility with the propellant. However, cleansing agents using a foamable aerosol composition composed of an oil-in-water (O/W) emulsion are not appropriate as detergents for oily cosmetics, because they contain an aqueous phase as a continuous phase and thereby have poor miscibility with and poor detergency for oily cosmetics. Known foamable cleansing agents having improved detergency for oily cosmetics include water-in-oil (W/O) compositions for oily foamable aerosols, which contain a polyoxyethylene-added nonionic surfactant, an alkyl phosphate derivative, and a polyglycerol fatty acid ester, respectively (see Japanese Unexamined Patent Application Publication (JP-A) No. 2004-75589; PCT International Publication Number WO 2003/035015; and Japanese Unexamined Patent Application Publication (JP-A) No. 2006-347896). These water-in-oil (W/O) compositions for oily foamable aerosols, however, often suffer from phase transition from a water-in-oil (W/O) phase to an oil-in-water (O/W) phase upon cleansing of cosmetics and are difficult to use when used under wet conditions. Additionally, they have still insufficient detergency. Specifically, there has not yet been known a detergent composition which is useable as a foamable cleansing agent kind to the skin, exhibits superior detergency for oily cosmetics, and is usable even under wet conditions.